const express = require('express');
const router = express.Router();
const nodemailer = require('nodemailer');
const config = require('../config');

// Helper function to create email transporter
const createTransporter = () => {
  return nodemailer.createTransport({
    host: config.email.host,
    port: config.email.port,
    auth: {
      user: config.email.user,
      pass: config.email.pass
    }
  });
};

module.exports = (pool, query, authMiddleware) => {
  // Apply authentication middleware to all routes
  router.use(authMiddleware);
  
  // Get all orders (admin only)
  router.get('/', async (req, res, next) => {
    try {
      // Check if user is admin
      if (!req.user.is_admin) {
        return res.status(403).json({
          error: true,
          message: 'Admin access required'
        });
      }
      
      const result = await query(`
        SELECT o.*, 
               u.email, u.first_name, u.last_name,
               COUNT(oi.id) AS item_count
        FROM orders o
        JOIN users u ON o.user_id = u.id
        LEFT JOIN order_items oi ON o.id = oi.order_id
        GROUP BY o.id, u.id
        ORDER BY o.created_at DESC
      `);
      
      res.json(result.rows);
    } catch (error) {
      next(error);
    }
  });
  
  // Get single order with items
  router.get('/:id', async (req, res, next) => {
    try {
      const { id } = req.params;
      
      // Check if user is admin
      if (!req.user.is_admin) {
        return res.status(403).json({
          error: true,
          message: 'Admin access required'
        });
      }
      
      // Get order details with shipping information
      const orderResult = await query(`
        SELECT o.*, 
               u.email, 
               u.first_name, 
               u.last_name,
               (SELECT EXISTS(
                 SELECT 1 FROM notification_logs
                 WHERE order_id = o.id AND notification_type = 'shipping_notification'
               )) as notification_sent
        FROM orders o
        JOIN users u ON o.user_id = u.id
        WHERE o.id = $1
      `, [id]);
      
      if (orderResult.rows.length === 0) {
        return res.status(404).json({
          error: true,
          message: 'Order not found'
        });
      }
      
      // Get order items with product details
      const itemsResult = await query(`
        SELECT oi.*, 
               p.name as product_name, 
               p.description as product_description,
               pc.name as product_category,
               (
                 SELECT json_agg(
                   json_build_object(
                     'id', pi.id,
                     'path', pi.image_path,
                     'isPrimary', pi.is_primary,
                     'displayOrder', pi.display_order
                   ) ORDER BY pi.display_order
                 )
                 FROM product_images pi
                 WHERE pi.product_id = p.id
               ) AS product_images
        FROM order_items oi
        JOIN products p ON oi.product_id = p.id
        JOIN product_categories pc ON p.category_id = pc.id
        WHERE oi.order_id = $1
      `, [id]);
      
      // Combine order with items
      const order = {
        ...orderResult.rows[0],
        items: itemsResult.rows
      };
      
      res.json(order);
    } catch (error) {
      next(error);
    }
  });
  
  // Update order status (simple version)
  router.patch('/:id', async (req, res, next) => {
    try {
      const { id } = req.params;
      const { status } = req.body;
      
      // Check if user is admin
      if (!req.user.is_admin) {
        return res.status(403).json({
          error: true,
          message: 'Admin access required'
        });
      }
      
      // Validate status
      const validStatuses = ['pending', 'processing', 'shipped', 'delivered', 'cancelled', 'refunded'];
      if (!validStatuses.includes(status)) {
        return res.status(400).json({
          error: true,
          message: `Invalid status. Must be one of: ${validStatuses.join(', ')}`
        });
      }
      
      // Update order status
      const result = await query(`
        UPDATE orders
        SET status = $1, updated_at = NOW()
        WHERE id = $2
        RETURNING *
      `, [status, id]);
      
      if (result.rows.length === 0) {
        return res.status(404).json({
          error: true,
          message: 'Order not found'
        });
      }
      
      res.json({
        message: 'Order status updated successfully',
        order: result.rows[0]
      });
    } catch (error) {
      next(error);
    }
  });
  
  // Update order status with shipping information and send notification
  router.patch('/:id/shipping', async (req, res, next) => {
    try {
      const { id } = req.params;
      const { status, shippingData, sendNotification } = req.body;
      
      // Check if user is admin
      if (!req.user.is_admin) {
        return res.status(403).json({
          error: true,
          message: 'Admin access required'
        });
      }
      
      // Validate status
      const validStatuses = ['pending', 'processing', 'shipped', 'delivered', 'cancelled', 'refunded'];
      if (!validStatuses.includes(status)) {
        return res.status(400).json({
          error: true,
          message: `Invalid status. Must be one of: ${validStatuses.join(', ')}`
        });
      }
      
      // Get order with customer information before updating
      const orderResult = await query(`
        SELECT o.*, u.email, u.first_name, u.last_name
        FROM orders o
        JOIN users u ON o.user_id = u.id
        WHERE o.id = $1
      `, [id]);
      
      if (orderResult.rows.length === 0) {
        return res.status(404).json({
          error: true,
          message: 'Order not found'
        });
      }
      
      const order = orderResult.rows[0];
      
      // Begin transaction
      const client = await pool.connect();
      
      try {
        await client.query('BEGIN');
        
        // Store shipping information as JSON in the database
        const updatedOrder = await client.query(`
          UPDATE orders
          SET 
            status = $1, 
            updated_at = NOW(),
            shipping_info = $2,
            shipping_date = $3
          WHERE id = $4
          RETURNING *
        `, [
          status, 
          JSON.stringify(shippingData),
          new Date(), 
          id
        ]);
        
        // If status is 'shipped' and notification requested, send email
        if (status === 'shipped' && sendNotification) {
          // Get order items for the email
          const itemsResult = await client.query(`
            SELECT oi.*, p.name as product_name, p.price as original_price
            FROM order_items oi
            JOIN products p ON oi.product_id = p.id
            WHERE oi.order_id = $1
          `, [id]);
          
          const orderItems = itemsResult.rows;
          
          // Send email notification
          await sendShippingNotification(
            order, 
            orderItems, 
            shippingData
          );
          
          // Log the notification in the database
          await client.query(`
            INSERT INTO notification_logs (order_id, notification_type, sent_at)
            VALUES ($1, $2, NOW())
          `, [id, 'shipping_notification']);
        }
        
        await client.query('COMMIT');
        
        res.json({
          message: 'Order status updated successfully',
          order: updatedOrder.rows[0]
        });
      } catch (error) {
        await client.query('ROLLBACK');
        throw error;
      } finally {
        client.release();
      }
    } catch (error) {
      console.error('Error updating order status with shipping:', error);
      next(error);
    }
  });
  
  // Helper function to send shipping notification email
  async function sendShippingNotification(order, orderItems, shippingData) {
    try {
      const transporter = createTransporter();
      
      // Calculate order total
      const orderTotal = orderItems.reduce((sum, item) => {
        return sum + (parseFloat(item.price_at_purchase) * item.quantity);
      }, 0);
      
      // Format shipping date
      const shippedDate = new Date(shippingData.shippedDate || new Date()).toLocaleDateString();
      
      // Generate items HTML table
      const itemsHtml = orderItems.map(item => `
        <tr>
          <td style="padding: 10px; border-bottom: 1px solid #eee;">${item.product_name}</td>
          <td style="padding: 10px; border-bottom: 1px solid #eee;">${item.quantity}</td>
          <td style="padding: 10px; border-bottom: 1px solid #eee;">$${parseFloat(item.price_at_purchase).toFixed(2)}</td>
          <td style="padding: 10px; border-bottom: 1px solid #eee;">$${(parseFloat(item.price_at_purchase) * item.quantity).toFixed(2)}</td>
        </tr>
      `).join('');
      
      // Generate carrier tracking link
      let trackingLink = '#';
      const shipper = shippingData.shipper || '';
      const trackingNumber = shippingData.trackingNumber;

      if (trackingNumber) {
        // Match exactly with the values from the dropdown
        switch(shipper) {
          case 'USPS':
            trackingLink = `https://tools.usps.com/go/TrackConfirmAction?tLabels=${trackingNumber}`;
            break;
          case 'UPS':
            trackingLink = `https://www.ups.com/track?tracknum=${trackingNumber}`;
            break;
          case 'FedEx':
            trackingLink = `https://www.fedex.com/apps/fedextrack/?tracknumbers=${trackingNumber}`;
            break;
          case 'DHL':
            trackingLink = `https://www.dhl.com/global-en/home/tracking.html?tracking-id=${trackingNumber}`;
            break;
          case 'Canada Post':
            trackingLink = `https://www.canadapost-postescanada.ca/track-reperage/en#/search?searchFor=${trackingNumber}`;
            break;
          case 'Purolator':
            trackingLink = `https://www.purolator.com/en/shipping/track/tracking-number/${trackingNumber}`;
            break;
          default:
            // For "other" or any carrier not in our list
            // Just make the tracking number text without a link
            trackingLink = '#';
            break;
        }
      }
      
      // Build email HTML
      const emailHtml = `
        <div style="font-family: Arial, sans-serif; max-width: 600px; margin: 0 auto;">
          <div style="background-color: #f8f8f8; padding: 20px; text-align: center;">
            <h1 style="color: #333;">Your Order Has Shipped!</h1>
            <p style="font-size: 16px;">Order #${order.id.substring(0, 8)}</p>
          </div>
          
          <div style="padding: 20px;">
            <p>Hello ${order.first_name},</p>
            
            <p>Good news! Your order has been shipped and is on its way to you.</p>
            
            ${shippingData.customerMessage ? `<p><strong>Message from our team:</strong> ${shippingData.customerMessage}</p>` : ''}
            
            <div style="background-color: #f8f8f8; padding: 15px; margin: 20px 0; border-left: 4px solid #4caf50;">
              <h3 style="margin-top: 0;">Shipping Details</h3>
              <p><strong>Carrier:</strong> ${shippingData.shipper || 'Standard Shipping'}</p>
              <p><strong>Tracking Number:</strong> <a href="${trackingLink}" target="_blank">${shippingData.trackingNumber}</a></p>
              <p><strong>Shipped On:</strong> ${shippedDate}</p>
              ${shippingData.estimatedDelivery ? `<p><strong>Estimated Delivery:</strong> ${shippingData.estimatedDelivery}</p>` : ''}
            </div>
            
            <div style="margin-top: 30px;">
              <h3>Order Summary</h3>
              <table style="width: 100%; border-collapse: collapse;">
                <thead>
                  <tr style="background-color: #f2f2f2;">
                    <th style="padding: 10px; text-align: left;">Item</th>
                    <th style="padding: 10px; text-align: left;">Qty</th>
                    <th style="padding: 10px; text-align: left;">Price</th>
                    <th style="padding: 10px; text-align: left;">Total</th>
                  </tr>
                </thead>
                <tbody>
                  ${itemsHtml}
                </tbody>
                <tfoot>
                  <tr>
                    <td colspan="3" style="padding: 10px; text-align: right;"><strong>Total:</strong></td>
                    <td style="padding: 10px;"><strong>$${orderTotal.toFixed(2)}</strong></td>
                  </tr>
                </tfoot>
              </table>
            </div>
            
            <div style="margin-top: 30px; border-top: 1px solid #eee; padding-top: 20px;">
              <p>Thank you for your purchase! If you have any questions, please contact our customer service.</p>
            </div>
          </div>
          
          <div style="background-color: #333; color: white; padding: 15px; text-align: center; font-size: 12px;">
            <p>&copy; ${new Date().getFullYear()} Rocks, Bones & Sticks. All rights reserved.</p>
          </div>
        </div>
      `;
      
      // Send the email
      await transporter.sendMail({
        from: config.email.reply,
        to: order.email,
        subject: `Your Order #${order.id.substring(0, 8)} Has Shipped!`,
        html: emailHtml
      });
      
      console.log(`Shipping notification email sent to ${order.email}`);
      return true;
    } catch (error) {
      console.error('Error sending shipping notification:', error);
      throw error;
    }
  }
  
  return router;
};